Mineral oil composition



Patented Jan. 11, 1949 MINERAL OIL COMPOSITION Edward A. Oberrlght, Woodbury, N. J., assignor to Socony-Vacuum Oil Company, Incorporated, a corporation of New York No Drawing. Application July 6, 1945, Serial No. 603.592

Claims. I

This invention has to do in a general way with mineral oil compositions and is more particularly related to compositions comprised of mineral oil and a minor proportion of an added ingredient which will improve the oil in one or more important respects.

It is well known to those familiar with the art that mineral oil fractions refined for their various uses are in and of themselves usually deficient in one or more respects so that their practical utility is limited even in the particular field for which they have been refined. For example, mineral oil fractions refined for use as lubricants have a tendency to oxidize under conditions of use, with the formation of sludge or acidic oxidation products; also, the lighter fractions such as gasoline and kerosene tend to oxidize with the formation of color bodies, gum, etc. In order to prevent the formation of these products and thereby extend the useful life of the oil fraction, it is common practice to blend with such oil fraction an additive ingredient which will inhibit oxidation, such ingredients being known to the trade as oxidation inhibitors, antioxidants, sludge inhibitors, gum inhibitors, etc.

It is also the practice to add other ingredients to mineral oil fractions for the purpose of improving "oiliness characteristics and the wearreducing action of such mineral oils when they are used as lubricants, particularly when the oils are used for the purpose of lubricating metal surfaces which are engaged under extremely high pressures and at high rubbing speeds.

Various other ingredients have been developed for the purpose of depressing the pour point of mineral oil fractions which have been refined for use as lubricants. Most refining treatments provide oils containing a small amount of wax which, without the added ingredient, would tend to crystallize at temperatures which render the oil impracticable for use under low temperature conditions. Additive agents have also been developed for improving the viscosity index of lubricating oil fractions. In the case of internal combustion engines, particularly those operating with high cylinder pressures. there is a decided tendency for the ordinary lubricating oil fractions to form carbonaceous deposits which cause the piston rings to become stuck in their slots and which ill] the slots in the oil ring or rings, thus materially reducing the efliclency of the engine. In-

gradients have been developed which, when added to the oil, will reduce this natural tendency of the oil to form deposits which interfere with the function of the piston rings.

It has also been discovered that certain types of recently-developed hard metal alloys, such as cadmium-silver alloy bearings, are attacked by ingredients in certain types of oils, particularly oils of high viscosity index obtained by various methods of solvent-refining. This corrosive action on such alloys has led to the development of corrosion-inhibitors which may be used in solvent-refined oils to protect such bearing metals against this corrosive action.

In the lighter mineral oil fractions, such as those used for fuel purposes, particularly in internal combustion engines, it has been found that the combustion characteristics of the fuel may be controlled and improved by adding minor proportions of various improving agents thereto.

The various ingredients which have been developed for use in mineral oil fractions to improve such fractions in the several characteristics enumerated above are largely specific to their particular applications. Therefore, it has been the practice to add a separate ingredient for each of the improvements which is to be effected.

The present invention is predicated upon the discovery of a group or class of oil-soluble reaction products or compounds which, when added to mineral oil fractions in minor proportions, will improve the oil fractions in several respects.

The novel addition agents contemplated by this invention as multifunctional improvers for mineral oils are oil-soluble, sulfur-containing reaction products obtained by reacting an aldehyde, a hydroxyaromatlc compound and a polyamine in which each amino group is characterized by the presence of at least one hydrogen atom to form a condensation product, and thereafter reacting the latter with elementary sulfur or a sulfur halide, or a mixture thereof. Preferred sulfur-containing reaction products are those obtained by condensing about one molar equivalent of an aldehyde with at least one-half molar equivalent of a polyamine of the aforesaid character and with a quantity of an alkyl-substituted hydroxy aromatic compound sufllcient that the content of the hydroxy aromatic substituent is about one molar equivalent, followed by reaction with at least one molar equivalent of one of the aforesaid sulfur reactants. Metal salts of these sulfur-containing reactfon products are also contemplated herein.

Aldehydes contemplated by the present invention are the aliphatic aldehydes, typified by formaldehyde (such as trioxymethylene), acetaldehyde, and aldol (B-hydroxy butyraldehyde); aromatic aldehydes. representative of which is benzaldehyde; heterocyclic aldehydes, such as iurfural; etc. The aldehyde may contain a substituent group such as hydroxyl, halogen, nitro and the like; in short, any substituent which does not take a major part in the reaction. Preference, however, is given to the aliphatic aldehydes, formaldehyde being particularly preferred.

The polyamines contemplated herein are those in which each amino group is characterized by the presence of at least one hydrogen atom. Such polyamines may contain only primary amino groups, only secondary amino groups, or both primary and secondary groups. Typical polyamines are the aliphatic homologs, ethylene diamine, propylene diamine; polyallrene polyamines (e. g. diethylene trlamine, triethylene tetra-mine); the aromatic homologs, mand p-phenylene diamine, diamino naphthalenes, etc. Of this class of amines, preference is given to the diamines in which two primary amino groups are attached to acUacent carbon atoms, and particular preference is accorded ethylene diamine.

Representative hydroxyaromatic compounds contemplated by the present invention are phenol, resorcinol, hydroquinone, catechol, cresol,

xylenol. hydroxydiphenyl, benzylphenol, phenylethylphenol, phenol resins, methylhydroxydiphenyl, guiacol, alpha and beta naphthol, alpha and beta methylnaphthol, tolylnaphthol, xylylnaphthol, benzylnaphthol, anthranol, phenylmethylnaphthol, phenanthrol. monomethyl ether of catechol, phenoxyphenol, chlorphenol, and the like. Preference in general is to the monohydroxy phenols otherwise unsubstituted, particular preference being given to phenol and alpha and beta naphthol.

The hydroxyaromatic compounds may also contain one or more substituent groups such as carboxyl, metal carboxylate, halogen, nitro and the like; here again. any substituent which does not take a predominant part in the condensation with the aldehyde and the polyamine. Preferred of such substituents is a carboxyl group.

As indicated hereinabove, the hydroxyaromatic compound may contain one or more alkyl substituents such as short-chain groups, typified by methyl, ethyl, amyl, etc.; or long-chain, relatlvely-high-molecular-weight hydrocarbon groups having at least twenty carbon atoms, typified by Mini groups derived from petroleum wax, which is a predominantly straight-chain aliphatic hydrocarbon of at least twenty carbon atoms. It will be obvious to those skilled in the art that the maximum number of alkyl groups is limited by the number of valences on the aromatic nucleus available for substitution. Naturally, the maximum number of such groups which can be attached to a. single aromatic nucleus will vary as the nucleus is monoor poly-cyclic and as the nucleus is otherwise substituted, with such groups as carboxy, nitro, amino, halogen and the like.

The present application has been purposely directed to condensation products of the aforesaid reactants for. as yet, the theory of reaction is not fully understood. some evidence is availableior example. quantitative analysis of the reaction product-to point to the presence of a wherein R is an alkyl group.

Probably also present in the condensation product are compounds of the following type:

It will be apparent. therefore, that when the condensation product is reacted with elementary sulfur or a sulfur halide, or a mixture thereof, the final product obtained thereby is of greater chemical complexity. For this reason, it will be clear that the foregoing is for illustrative purposes only and is not to be construed as limiting the present invention to a theory of reaction because the present invention is directed primarily to condensation products obtained by interreaction oi the reactants described herein as multifunctional improving agents for lubricating oils and the like.

In preparing the intermediate or condensation products contemplated herein, the reactants may be added to each other in any order. A typical procedure involves adding the aldehyde to an alcohol solution of the hydroxy aromatic compound and the mine. The reaction may also be carried out in the presence of other diluents or solvents such, for example, as tctrachlorethane. chlorbenzene, mineral oil, etc. In. the event that mineral oil is used as a diluent, the mineral oil may be retained, rather than separated from the reaction product, thereby providing a mineral oil concentrate.

The reaction temperature may be varied considerably, depending upon the time of reaction, the specific reactants used, etc. For example. the reaction can be carried out at room temperature over a relatively long period of time or at the reflux temperature of the solvent over a comparatively short period. By way of illustration, the reactants, in quantities such as shown in the following examples, may be thoroughly mixed at room temperature for several hours and the reaction completed at the reflux temperature of the solvent for an additional period of several hours.

The reaction product may be water washed to assure complete removal of any unreacted amine and this is recommended when the amine is high boiling. When an alcohol is used as a diluent in the reaction, it is distilled from the reaction mixture, thereby also removing any unreacted amine and water of reaction or water added with the reactants (Formaiin, for example, is generally used in a 37 per cent aqueous solution).

As stated above, the general procedure for preparing the contemplated condensation products involves the interreactlon of a hydroxyaromatic compound, an aliphatic aldehyde, and a polyamine wherein the amino groups have at least one free hydrogen.

A typical, and also preferred, alkyl-substituted hydroxyaromatic compound which may be used is a wax-substituted phenol, wax-phenol." The term wax" as used herein designates petroleum wax or aliphatic hydrocarbons or hydrocarbon groups of the type which characterize petroleum wax. These so-calied wax" substituents may be obtained by alkylation of the phenol or hydroxyaromatic hydrocarbon with a relativelyhigh-molecular weight aliphatic hydrocarbon or mixture of such hydrocarbons (such as petroleum wax) by any suitable alkylation procedure such, for example, as by a Friedel-Crafts condensation of chlorinated petroleum wax with phenol.

As indicated hereinabove, the reaction products contemplated herein are prepared by reacting a condensation product of the type described above with elementary sulfur, a sulfur halide or a mixture thereof. This reaction is preferably carried out in the presence of an inert diluent such as tetrachlorethane, benzene, chlorbenzene, mineral oil, etc. These diluents--except heavy mineral oils-ar-e removed after the reaction by distillation of the reaction mixture which conv tains the desired reaction product. When mineral oil is used as the diluent, however, it may be retained, thereby providing a mineral oil concentrate containing the reaction product.

I'he reaction temperature may be varied considerably, depending upon the reaction time and the specific sulfurizing reactant used. Generally, higher reaction temperatures and longer reaction times are required when elementary sulfur is used than when a sulfur halide is used. The preferred procedure involves adding the sulfurizing reactant to the condensation product at -25 C. and thereafter heating the reaction mixture so formed at the reflux temperature of the diluent for several hours. Preference is given the sulfur halides and, of these, sulfur monochloride is particularly pre'frred.

Metal salts of the aforesaid sulfur-containing reaction products, as indicated above, also fall within the scope of the present invention. Any

metal may be used the oxide or hydroxide of which (in alcohol solution, if necessary) can be reacted with the intermediate condensation product, or a salt of which can be reacted in alcohol solution with the sodium salt of the intermediate product. Among the metals contemplated for this purpose are: copper, beryllium, magnesium, calcium, strontium, barium, radium, zinc, cadmium, mercury, germanium, tin, lead, vanadium, chromium, manganese, iron, cobalt, nickel. ruthenium, palladium, platinum, aluminum, antimony, arsenic, bismuth, cerium, columbium, gallium, gold, indium, iridium, molybdenum, osmium, rubidium, selenium, tantalum, tellurium, thorium, titanium, tungsten, uranium, and zirconium. Preference is given to metals of the alkaline earth group, particularly to barium. As noted above, the metal is preferably introduced by reaction of its oxide or hydroxide with the intermediate condensation product. Where necessary, an alcohol solution of the oxide or hydroxide is used. The metal salts can also be prepared by reacting the sodium salt of the intermediate product with an alcohol solution of a salt of the desired metal, such as stannous chloride, lead acetate, thorium nitrate. titanium tetrachloride, etc.

Details of a preferred procedure for making the condensation products of this invention where the aforesaid wax-phenol is employed as the alkylsubstituted hydroxyaromatic compound may be obtained from the following examples:

EXAMPLE A. Alkulation of phenol A paraffin wax melting at approximately F. and predominantly comprised of compounds having at least twenty carbon atoms in their molecules is melted and heated to about 200 F., after which chlorine is bubbled therethrough until the wax has absorbed about 16 per cent of chlorine, such product having an average composition between a monochlor wax and a dichlor wax. Preferably, the chlorination is continued until about one-sixth the weight of the chlor-wax" formed is chlorine. A quantity of chlorwax thus obtained, containing two atomic proportions of chlorine, is heated to a temperature varying from just above its melting point to not over F., and one moi of phenol (CaHsOH) is admixed therewith. The mixture is heated to about 150 F., and a quantity of anhydrous aluminum chloride corresponding to about 3 per cent of the weight of chlorwax in the mixture is slowly added with active stirring. The rate of addition of the aluminum chloride should be sufficiently slow to avoid violent foaming, and during such addition the temperature should be held at about 150 F. After the aluminum chloride has been added, the temperature of the mixture may be increased slowly over a period of from 15 to 25 minutes to a temperature of about 250 F. and then should be more slowly increased to about 350 F. To control the evolution of HCl gas the temperature of the mixture is preferably raised from 250 F. to 350 F. at a rate of approximately one degree per minute, the whole heating operation occupying approximately two hours from the time of adding the aluminum chloride. If the emission of HCl gas has not ceased when the final temperature is reached, the mixture may be held at 350 F. for a short time to allow completion of the reaction. However, to avoid possible cracking of the wax, the mixture should not be heated appreciably above 350 F.,

nor should it be held at that temperature for any extended length of time.

It is important that all unreacted or non-alkylated hydroxyaromatic material (phenol) remaining after the alkylation reaction be removed. Such removal can be effected generally by waterwashing, but it is preferable to treat the waterwashed product with superheated steam, thereby insuring complete removal of the unreacted material and accomplishing the drying of the product in the same operation.

A wax-substituted phenol prepared according to the above procedure in which a quantity of chlorwax containing two atomic proportions of chlorine and having a chlorine content of 16 per cent is reacted with one mol of phenol will be hereinafter designated as wax-phenol(2-16).

B. Formation of condensation product One hundred and fifty grams of wax-phenol (2-14) prepared according to the foregoing procedure, and 20.8 grams of a 69 per cent solution of ethylene diamine in water were dissolved in butyl alcohol. To the resulting alcohol solution, 19.5 grams of a 3'! per cent aqueous solution of formaldehyde in water-Formalin-were added dropwise, and the reaction mixture was stirred for 3% hours at room temperature (about 25 0.). The reaction was allowed to stand for 16 hours and thereafter heated for 7% hours at reflux, about 110 C. The reaction mixture thus obtained was water washed until the washings were neutral. Butyl alcohol was removed from the water-washed reaction mixture by distilling the latter to a maximum temperature of 190 C. at 10 mms. pressure, thereby obtaining the condensation product.

C. Sulfur-containing condensation product Fifty grams of the condensation product obtained in 3, above, were dissolved in 100 grams of mineral oil having an S. U. V. of 65 seconds at 210 F. Tetrachlorethane, an inert diluent, was then added to the mineral oil solution. Sulfur monochioride (4.8 grams) was added slowly at room temperature, about 25 C. After all of the sulfur monochloride was added, the reaction mixture thus obtained was heated at 100 C. for two hours. The reaction mixture was then washed with dilute ammonia to remove any hydrochloric acid complexes that might have formed in the reaction, by the action of evolved HC] on the reaction product. This was followed by a dilute acetic acid wash and the diluent, tetrachlorethane, was removed by distillation to a maximum temperature of 175 C. at 10 mms. pressure. The reaction product (Product One) is a 1:2 blend in mineral oil, and the blend has a sulfur content of 1.5 per cent.

D. Stannous salt of sulfur-containing condensation product Sodium metal (0.69 gram), in small pieces in butyl alcohol, was added to 60 grams of the oil blend obtained in C above. thereby forming the sodium salt. Three grams of stannous chloride in butyl alcohol were then added at room temperature (25 C.) and the resulting reaction mixture was heated at 120 C. for two hours. The reaction mixture was then filtered through Hi- Flo" clay, thereby removing sodium chloride formed by reaction of the sodium salt and stannous chloride. Butyl alcohol was distilled from the filtrate by distilling the latter to a maximum temperature of 175 C. at 10 mms. pressure, thereby providing the final product (Product Two) in approximately a 1:2 011 blend. The oil blend contained 1.4 per cent sulfur and 3.4 per cent tin.

As stated hereinbefore, the reaction products contemplated b this invention and illustrated by the above examples, when added to lubricating oils in minor proportions, have been found to improve these oils in several important respects. This phenomenon is demonstrated by the following tables. which give the results of the various tests conducted to determine the effectiveness of these reaction products as addition agents for lubricating oils. The per cent of material added to the oil in the following tables is the'per cent of concentrated material and does not include the oil in which the product was made.

POUR Pomr Dsraassron Table I A. S. T. M. Pour Point Values Per Cent Addition Ag n Added o Product Two Do Vrscosrrr INDEX IMPROVEMENT A mineral oil of 41.8 seconds Saybolt Universal viscosity at 210 F. was tested in the conventional manner to determine the improvement in viscosity index values effected by various of the reaction products contemplated by this invention. This improvement is clearly demonstrated by the results set forth in Table II below.

Conaosrorz 'Insr In this test the reaction product was blended with a Pennsylvania solvent-refined oil of Baybolt Universal viscosity of 53 seconds at 210 F., and a section of a bearing containing a cadmiumsilver alloy surface and weighing about 6 grams was added to this blend. The oil was heated to C. for 22 hours while a stream of air was bubbled against the surface of the bearing. The loss in weight of the bearing during this treatment measured the amount of corrosion that had taken place. A sample of the straight oil was subjected to the same test at the same time, and the difference between the losses in weight of the two bearing sections demonstrated conclusively the effectiveness of the reaction products contempiated herein as corrosion-inhibitors.

SOCONY-VACUUM TURBINE Tas'r Twenty-five cc. samples of a furfural-refined Rodessa crude oi Saybolt Universal viscosity of 150 seconds at 100 F. and of blends of this same 011 and typical reaction products were subjected to the following test to determine the effectiveness of the reaction products contemplated by this invention as inhibitors for turbine oils: To each sample were added 1 gram of iron granules and 24 inches of 18 gauge copper wire. The samples were then heated to a temperature of 200 F. with 5 liters of air per hour bubbling therethrough. Two cc. of distilled water were added each day. The results of the tests which were made for color and acidity or neutralization number and amount of sludge formed after certain time intervals are set forth in Table IV below.

OPERATION TEST To demonstrate the effectiveness of the reaction products under actual operating conditions of an automotive engine, unblended oils and improved oiis, containing the reaction products, were subjected to the Lauson engine test. The tests were carried out in a single-cylinder Lauson engine operated continuously over a time interval of 16 hours with the cooling medium held at a temperature of about 212 F., and the oil temperature held at about 280 F. The engine was operated at a speed of about 1830 R. P. M. At the end of each test the oil was tested for acidity (N. N.) and viscosity. The base oil used here is a solvent refined oil having an S. U. V. of 44 seconds at 210 F.

I Table V Addition Agent f gg gg ds i N. N

06. 07 11.2 48. 72 3. 2 50 77 7. 2 Product Two 48. 66 3. 9

metallic reaction products, whereas the latter have superior detergent action.

The amount of improving agent used varies with the mineral oil or lubricating oil traction with which it is blended and with the properties desired in the final oil composition. These reaction products may be added to mineral oil in amounts of from about 0.001 to about 10 per cent, but amounts of from about 0.1 per cent to about 3 per cent generally provide satisfactory improvement.

It is to be understood that although I have described certain preferred procedures which may be followed in the preparation of the novel reaction products contemplated herein as multifunctional addition agents tor mineral oils and have indicated representative reactants for use in their preparation, such procedures and reactants are merely illustrative and the invention is not to be considered as limited thereto or thereby but includes within its scope such changes and modifications as fairly come within the spirit of the appended claims.

I claim:

1. An improved mineral oil containing a minor proportion, sufficient to inhibit said oil against the deleterious effects of oxidation, of an oilsoluble, sulfur-containing reaction product obtained by reacting an aldehyde, 9. hydroxyaromatic compound and a polyamine in which each amino group has at least one hydrogen atom, in the ratio, on the basis of one molar equivalent of the aldehyde, of at least about one-half molar equivalent to the polyamine and about one molar equivalent of the hydroxyaromatic compound, in the presence 01 an inert solvent, at a temperature falling within the range varying betw en about room temperature and the reflux tern rature of the solvent and for a time suificient to effect condensation, to produce a condensation product, and reacting said product with a sulfurlzing material selected from the group consisting of elementary sulfur, a sulfur halide and a mixture thereof in the ratio corresponding to about one molar equivalent of sulfurizing material per molar equivalent of aldehyde employed in producing said condensation product, in the presence of an inert diluent at a temperature falling within the range varying between about 20 C. and the reflux temperature of the inert diluent, and for a time suificient to efiect sulfurizatlon of said condensation product.

2. An improved mineral oil containing a minor proportion, from about 0.001 per cent to about 10 per cent, of an oil-soluble, sulfur-containing reaction product obtained by reacting an aldehyde, a hydroxyaromatic compound and a polyamine in whicheach amino group has at least one hydrogen atom, in the ratio, on the basis of one molar equivalent of the aldehyde, of at least about one-half molar equivalent of the polyamine and about one molar equivalent of the hydroxyaromatic compound, in the presence of an inert solvent, at a temperature fallin within the range varying between about room temperature and the reflux temperature of the solvent and for a time suflicient to effect condensation, to produce a condensation product, and reacting said product with a. suliurizing material selected from the group consisting of elementary sulfur, a sulfur halide and a mixture thereof in the ratio corresponding to about one molar equivalent of sulfurizing material per molar equivalent of aldehyde employed in producin said condensation product, in the presence of an inert diluent at a temperal l ture falling within the range varying between about C. and the reflux temperature of the inert diluent, and for a time sufficient to effect sulfurization of said condensation product.

3. An improved mineral oil containing a minor proportion, sufficient to inhibit said oil against the deleterious effects of oxidation of an oilsoluble, sulfur-containing reaction product obtalned by reacting an aldehyde, a hydroxyaromatic compound and a polyamlne in which each amino group has at least one hydrogen atom, in the ratio, on the basis of one molar equivalent of the aldehyde, of at least about one-half molar equivalent of the polyamlne and about one molar equivalent of the hydroxyaromatic compound, in the presence of an inert solvent at a temperature falling within the range varying within about room temperature and the reflux temperature of the solvent and for a time sufficient to eflect condensation, to produce a condensation product, and reacting said product with a sulfur halide in the ratio corresponding to about one molar equivalent of sulfur halide per molar equivalent of aldehyde employed in producing said condensation product, in the presence of an inert diluent at a temperature varying within the range between about 20 C. and the reflux temperature of the inert diluent, and for a time sufficient to effect sulfurization of said condensation product.

4. An improved mineral oil containing a minor proportion, sumcient to inhibit said oil against the deleterious effects of oxidation, of an oilsoluble, sulfur-containing reaction product obtained by reacting an aldehyde, a hydroxyaromatic compound and a polyamlne in which each amino group has at least one hydrogen atom, in the ratio, on the basis of one molar equivalent of aldehyde, of at least about one-half molar equivalent of the polyamlne and about one molar equivalent of the hydroxyaromatic compound, in v the presence of an inert solvent at a temperature falling within the range varying between about room temperature and the reflux temperature of the solvent and for a time sufficient to effect condensation, to produce a condensation product, and reacting said product with sulfur monochloride in the ratio corresponding to about one molar equivalent of sulfur monochloride per molar equivalent of aldehyde employed in producing said condensation product, in the presence of an inert diluent at a temperature falling within the range varying between about 20 C. and the reflux temperature of the inert diluent, and for a time sufficient to effect sulfurization of said condensation product.

5. An improved mineral oil containing a minor proportion, sufficient to inhibit said oil against the deleterious effects of oxidation, of an oilsoluble, sulfur-containing reaction product obtained by reacting an aldehyde, a hydroxyaromatic compound and a polyamlne in which each amino group has at least one hydrogen atom, in the ratio, on the basis of one molar equivalent of the aldehyde, of at least about one-half molar equivalent of the polyamlne and about one molar equivalent of the hydroxyaromatic compound, in the presence of an inert solvent at a temperature falling within the range varying between about room temperature and the reflux temperature of the solvent and for a time sufficient to effect condensation, to produce a condensation product, and reacting said product with elementary sulfur in the ratio corresponding to about one molar equivalent of sulfurizing material per molar equivalent of aldehyde employed in producing 12 said condensation product, in the presence of an inert diluent at a temperature falling within the range varying between about 20 C. and the reflux temperature of the inert diluent, and for a time sufficient to effect sulfurization of said condensation product.

6. An improved mineral oil containing a minor proportion, sufllcient to inhibit said oil against the deleterious effects of oxidation, of an oilsoluble, sulfur-containing reaction product obtained by reacting an aliphatic aldehyde, a bydroxyaromatic compound and a polyamlne in which each amino group has at least one hydrogen atom, in the ratio, on the basis of one molar equivalent of the aldehyde, of at least about onehalf molar equivalent of the polyamlne and about one molar equivalent of the hydroxyaromatic compound, in the presence of an inert solvent at a temperature falling within the range varying between about room temperature and the reflux temperature of the solvent and for a time sufficient to effect condensation, to produce a condensation product, and reacting said product with a sulfurizing material selected from the group consisting of elementary sulfur, a sulfur halide and a mixture thereof, in the ratio corresponding to about one molar equivalent of sulfurizing material per molar equivalent of aldehyde employed in producing said condensation product, in the presence of an inert diluent at a temperature falling within the range varying between about 20 C. and the reflux temperature of the inert diluent and for a time sufficient to effect suifurization of said condensation product.

7. An improved mineral oil containing a minor proportion, suiiiclent to inhibit said oil against the deleterious effects of oxidation, of an oilsoluble, sulfur-containing reaction product obtained by reacting formaldehyde, a hydroxyaro matic compound and a polyamlne in which each amino group has at least one hydrogen atom, in the ratio, on the basis of one molar equivalent of formaldehyde, of at least about one-half molar equivalent of the polyamlne and about one molar equivalent of the hydroxyaromatic compound, in the presence of an inert solvent at a temperature falling within the range varying between about room temperature and the reflux temperature of the solvent and for a time sufficient to effect condensation, to produce a condensation product, and reacting said product with a sulfurizing material selected from the group consisting of elementary sulfur, a sulfur halide and a mixture thereof in the ratio corresponding to about one molar equivalent of sulfurizing material per molar equivalent of aldehyde employed in producing said condensation product, in the presence of an inert diluent at a temperature falling within the range varying between about 20 C. and the reflux temperature of the inert diluent, and for a time suflicient to effect sulfurization of said condensation product.

8. An improved mineral oil containing a minor proportion, sufficient to inhibit said oil against the deleterious effects of oxidation, of an oilsoluble, sulfur-containing reaction product obtained by reacting an aldehyde, a hydroxyaromatic compound and an aliphatic polyamlne in which each amino group has at least one hydrogen atom, in the ratio, on the basis of one molar equivalent of the aldehyde and at least about one-half molar equivalent of the polyamlne and about one molar equivalent of the hydroxyaromatic compound, in the presence of an inert solvent at a temperature falling within the range varying between about room temperature and the reflux temperature of the solvent and for a time sufficient to effect condensation, to produce a condensation product, and reacting said product with a sulfurizing material selected from the group consisting of elementary sulfur, a sulfur 'hallde and a mixture thereof in the ratio corresponding to about one molar equivalent of sulfurizing material per molar equivalent of aldehyde employed in producing said condensation product, in the presence of an inert diluent at a temperature falling within the range varying between about 20 C. and the reflux temperature of the inert diluent, and for a time sufficient to effect sulfurization of said condensation product.

9. An improved mineral oil containing a minor proportion sufficient to inhibit said oil against the deleterious effects of oxidation of an oil-soluble, sulfur-containing reaction product obtained by reacting an aldehyde, a hydroxyaromatic compound and ethylene dlamine, in the ratio, on the basis of one molar equivalent of the aldehyde, and at least about onehalf molar equivalent of ethylene diamine and about one molar equivalent of the hydroxyaromatic compound, in the presence of an inert solvent at a temperature falling within the range varying between about room temperature and the reflux temperature of the solvent and for a time sufllcient to effect condensation, to produce a condensation product, and reacting said product with a sulfurizing material selected from the group consisting of elementary sulfur, a sulfur halide and a mixture thereof in the ratio corresponding to about one molar equivalent of sulfurizing material per molar equivalent of aldehyde employed in producing said condensation product, in the presence oi an inert diluent at a temperature falling within the range varying between about 20 C. and the reflux temperature of the inert diluent, and for a time sumcient to effect sulfurization of said condensation product.

10. An improved mineral oil containing a minor proportion, sufllcient to inhibit said oil against the deleterious effects of oxidation, of an oil-soluble, sulfur-containing reaction product obtained by reacting an aldehyde, an alkyl-substituted hydroxyaromatic compound and a polyamine in which each amino group has at least one hydrogen atom, in the ratio, on the basis of one molar equivalent of the aldehyde, and at least about one-half molar equivalent of the polyamine and a sufllcient amount of the alkyl-substituted hydroxyaromatic compound to provide about one molar equivalent of the hydroxyaromatic constituent thereof, in the presence of an inert solvent at a temperature falling within the range varying between about room temperature and the reflux temperature of the solvent and for a time sufllcient to effect condensation, to produce a condensation product, and reacting said product with a sulfurlzing material selected from the group consisting of elementary sulfur, a sulfur halide and a mixture thereof in the ratio corresponding to about one molar equivalent of sulfurizing material per molar equivalent of aldehyde employed in producing said condensation product, in the presence of an inert diluent at a temperature falling within the range varying between about 20 C. and the reflux temperature of the inert diluent, and for a time sumcient to eifect sulfurization of said condensation product.

11. An improved mineral oil containing a minor proportion, sufllcient to inhibit said 011 against the deleterious effects of oxidation, of an oilsoluble, sulfur-containing reaction product obtained by reacting an aldehyde, a wax-phenol and a polyamine in which each amino group has at least one hydrogen atom, in the ratio, on the basis of one molar equivalent of aldehyde, 0! at least about one-half molar equivalent of the polyamine and a sufllcient amount of the wax-phenol to provide about one molar equivalent of the phenol constituent thereof, in the presence of an inert solvent at a temperature falling within the range varying between about room temperature and the reflux temperature of the solvent and for a time suflicient to effect condensation, to produce a condensation product, and reacting said product with a suli'urizing material selected from the group consisting of elementary sulfur, a sulfur halide and a mixture thereof in the ratio corresponding to about one molar equivalent of sulfurizing material per molar equivalent of aldehyde employed in producing said condensation product in the presence of an inert diluent at a temperature falling within the range varying between about 20 C. and the reflux temperature of the inert diluent, and for a time suilicient to effect sulfurization of said condensation product.

12, An improved mineral oil containing a minor proportion, sufficient to inhibit said oil against the deleterious effects of oxidation of an oil-soluble, sulfur-containing reaction product obtained by reacting formaldehyde, wax-phenol and ethylene diamine in the ratio, on the basis of one molar equivalent of formaldehyde, of at least about one-half molar equivalent of ethylene diamine and a suflicient amount of wax-phenol to provide about one molar equivalent of the phenol constituent thereof, in the presence of an inert solvent at a temperature falling within the range varying between about room temperature and the reflux temperature of the solvent and for a time suflicient to effect condensation, to produce a condensation product, and reacting said product with sulfur monochloride in the ratio corresponding to about one molar equivalent of sulfur monochloride per molar equivalent of aldehyde employed in producing said condensation product, in the presence of an inert diluent at a temperature falling within the range varying between about 20 C, and the reflux temperature of the inert diluent, and for a time suflicient to effect sulfurization of said condensation product.

13. An improved mineral oil containing a mi nor proportion, sufficient to inhibit said oil against the deleterious effects of oxidation, of an oil-soluble, metaland sulfur-containing reaction product obtained by reacting an aldehyde, a hydroxyaromatic compound and a polyamine in which each amino group has at least one hydrogen atom in the ratio, on the basis of one molar equivalent of the aldehyde, of at least about one-half molar equivalent of the polyamine and about one molar equivalent of the hydroxyaromatic compound, in the presence of an inert solvent at a temperature falling within the range varying between about room temperature and the reflux temperature of the solvent and for a time sufllcient to effect condensation, to produce a condensation product, and reacting said product with a sulfurizing material selected from the group consisting of elementary sulfur, a sulfur halide and a mixture thereof, in the ratio corresponding to about one molar equivalent of sulfurizing material per mo- Iar equivalent of aldehyde employed in producing said condensation product, in the presence of an inert diluent at a temperature tailing within the range varying between about 20 C. and the reflux temperature 01' the inert diluent, and for a time suflicient to effect suliurization oi sai i condensation product, and introducing a metal into the sulfur-containing reaction product so obtained.

14. An improved mineral oil containing a mi nor proportion, from about 0.001 per cent to about 10 per cent, of an oil-soluble, metaland sulfurcontaining reaction product obtained by reacting an aldehyde, a hydroxyaromatic compound and a polyamine in which each amino group has at least one hydrogen atom in the ratio, on the basis of one molar equivalent oi aldehyde, 0! at least about one-half molar equivalent of the polyamine and about one molar equivalent of the hydroxyaromatlc compound, in the presence of an inert solvent at a temperature and the reflux temperature of the solvent and for a time sui'iicient to efiect condensation, to produce a condensation product, and reacting said product with a suifurizing material selected from the group consisting of elementary sulfur, a sulfur halide and a mixture thereof in the ratio corresponding to about one molar equivalent of sulfurizing material per molar equivalent of aldehyde employed in producing said condensation product, in the presence of an inert diluent at a temperature falling within the range varying between about 20 C. and the reflux temperature of the inert diluent, and for a time suiflcient to effect suliurization 01 said condensation product. and introducing a metal into the sulfur-containing reaction product so obtained.

15. An improved mineral oil containing a minor proportion, sufliclent to inhibit said oil against the deleterious effects of oxidation, 01' an oil-soluble, tinand sulfur-containing reaction product obtained by reacting formaldehyde, wax-pheml and ethylene diamine in the ratio. on the basis 01' one molar equivalent oi formaldehyde, 01 at least about one-half molar equivalent 0! ethylene diamlne and a suiiicient amount of waxphenol to provide about one molar equivalent of the phenol constituent thereof, in the presence of an inert solvent at a temperature falling within the range varying between about room temperature and the reflux temperature of the solvent for a time suflicient to eflect condensation, to produce a condensation product, and reacting said product wtih sulfur monochloride in the ratio corresponding to about one molar equivalent of sulfur monochloride per molar equivalent of alder hyde employed in producing said condensation product, in the presence of an ineris diluent at a temperature falling within the range varying between about 20 C. and the reflux temperature of the inert diluent, and for a time sufllcient to effect suliurization of said condensation product, and introducing tin into the sulfur-containlng reaction product so obtained.

EDWARD A. OBERRIGHT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,263,445 Reifl Nov. 18, 1941 2,282,710 Dietrich May 12, 1942 2,322,376 McCieary June 22, 1943 2,334,594 Zimmer Nov. 16, 1943 2,336,006 Fuller Dec. 7, 1943 2,340,036 Zimmer Jan. 25, 1944 2,353,192 Sargent July 11, 1944 2,353,491 Oberright Jul 11, 1944 2,363,134 McCleary Nov. 21, 1944 2,366,874 Reifl Jan. 9, 1945 2,414,729 Fleming Jan, 21, 1947 

